26 CFR 48.4161(b)-4 - Tax-free sales.
For provisions relating to tax-free sales of articles referred to in section 4161(b) see:
(a) Section 4221, relating to certain tax-free sales;
(b) Section 4222, relating to registration;
(c) Section 4223, pertaining to special rules relating to further manufacture; and
(d) Section 4225, relating to exemption of articles manufactured or produced by Indians;